Question

How do you simplify `(9 - sqrt2) (7 + sqrt2)`?

Answer 1

`61+2sqrt(2)`

Explanation:

First, to simplify this expression, you need to use the distributive property (or FOIL):
`(9-sqrt(2))(7+sqrt(2))`
`9(7)+9(sqrt(2)) -sqrt(2)(7) -sqrt(2)(sqrt(2))`
`63+9sqrt(2) -7sqrt(2) -sqrt(4)`

Now, you simplify:
`63+2sqrt(2)-2`
`63-2+2sqrt(2)`
`61+2sqrt(2)`